. >>> pope benedict changed the rule about his succession. religion correspondent lauren green explains there is uncertainty and controversy about the replacement process. >> pope benedict xvi signed a special legal document to clear the way for cardinals to move up the start date of the conclave once the papal seat is vacated. 15-day transition period to start the process and choose a new pope was set in 1996 and could only be changed by another pope. one of his last official acts before stepping down thursday. no date has been set for conclave to begin. >> we cannot expect it to take place before marm 1. we have no other information until cardinals decide and general congregation when the date will come. >> there is going to be one less cardinal voting in conclave. o'brien of scotland british highest ranking catholic leader is retiring and will not be attending. the resignation as archbishop of st. andrews and edinburgh is part of mandatory age requirement but comes in the wake of allegation of misconduct. british newspapers report o'brian